Deck 10: Introducing Inference: Estimation From Samples

Question 1

The purpose of inferential statistics is to make inferences about characteristics of the population from which the data were drawn.

Answer 1

True

Question 2

When both variables are categorical, the t-test should be used for hypothesis testing.

Answer 2

False

Question 3

When both variables are continuous, the χ² test should be used for hypothesis testing.

Answer 3

False

Question 4

When both variables are continuous, simple regression can be used.

Question 5

Multivariate statistics involve statistics for three or more variables.

Question 6

It is practical to survey the entire population of a city.

Question 7

The population is the entire set of subjects of interest in any study, and a sample is a portion or subset of the population.

Question 8

Statistical inference is about drawing conclusions about a population from sample data.

Question 9

The best way to draw a sample is randomly-each subject should have an equal chance of being selected as part of your sample.

Question 10

We use population parameters to estimate unknown sample statistics.

Question 11

The estimation error is the difference between a sample statistic and a population parameter.

Question 12

A confidence interval is defined the range within which the unknown but true population parameter is estimated to lie.

Question 13

A 95% confidence interval is sometimes expressed as stating that when drawing many samples, 5% of the times the mean will lie within a confidence interval.

Question 14

The Central Limit Theorem is fundamental statistical insight that allows us to make inferences from a single sample to the population.

Question 15

A probability distribution is a statistical function which describes all possible values and likelihoods that a variable can take.

Question 16

A normal distribution (Appendix

A) A) is an example of a probability distribution.

Question 17

The standard deviation of a probability distribution is also called a standard error.

Question 18

The formula for calculating a confidence interval for samples larger than 30 is .

Question 19

When the sample size is smaller than 30, the normal distribution is replaced by the t distribution for calculating confidence interval.

Question 20

Confidence intervals are also calculated for proportions (e.g., polling data)